Panel Movement

[LambrettaMarky]

Folks

After a short distance my right hand panel moves to this position. I usually fit them with a bit of silicone bike spray to ease them onto the rubber trim, then push it forward slightly to engage the rear trim..

However the right hand panel likes to reposition itself to here & to date stays put here rather than coming completely off:

RHS Panel by KTM Marky, on Flickr

Any suggestions what to adjust or a better way to install it most welcome?

Thx

LambrettaMarky

[Storkfoot]

Take the spring off. Put it in a sturdy vice. Take a lump hammer and smack the part that engages with that panel three of four times to bend it in.

You may need to do this a few times to get it right.

[Toddy]

I would take the rear shocker off and let the scooter bottom out see if anything is catching causing the panel to come loose first then look at Paul’s idea

[Adam_Winstone]

As Toddy has said, there is a very good chance that your panel is hitting your pipe under suspension travel. Likely to be hitting the vertical return of your rear runner too.

GP panels, and others that used the clip design, have an extensive history of popping off and getting damaged. I could bore you with quoting time after time that this has happened to me, my clubmates, my riding party members... but better to say that this has resulted in decades of people fitting panel locks to stop this from happening. Whilst many think that the readily available bolt-in type are a modern (not cool) solution, the 1972 example of a girl sitting on an extremely cool GP200 Electronic, with these panel locks fitted, is a great example of them not being a 'modern' solution, rather a 'period' solution to a very common problem.

The image that I mention is currently available at: https://hidesalevs.click/product_details/100150115.html

[Storkfoot]

Take the spring off. Put it in a sturdy vice. Take a lump hammer and smack the part that engages with that panel three of four times to bend it in.

You may need to do this a few times to get it right.

With hindsight, this remedy is more geared to the sturdier LI/SX type panel springs

[gaz_powell]

Thats a great picture... I would love that reg

[LambrettaMarky]

Thanks folks - will take a look and note the advice... Cheers..

[LambrettaMarky]

In fact this has only been happening post JL3 going on...

I will investigate.

[Warkton Tornado No.1]

The advice that has been given is all good & it’s relatively straightforward to check for interference with suspension movement & giving the spring clip a bias toward the LH side & even pre-loading to an extent.

Sometimes though, the panels can gain a ‘twist’ that probably comes about through the stress relieving post blasting for painting preparation. That has certainly been the case when I have had blasted & painted panels returned.

Any twist can be seen by laying a panel on a flat surface & if there is any it can usually be persuaded out without any effect on the finished paintwork. It may not be the best method of removing any twist but I’ve always gripped the front end between my thighs (Ooooer!) & tweaked the clip end with hands until the situation is improved.

[LambrettaMarky]

OK - Found the issue - See Pics:

Exhaust Interference 3 by KTM Marky, on Flickr

Exhaust Interference 2 by KTM Marky, on Flickr

Exhaust Interference 1 by KTM Marky, on Flickr

The inner edge of the panel where it's formed is hitting the nylon JL3 spacer/mount.

I don't want to cut the panel so can turn a step in the nylon bush or machine a dog leg type mount in mild steel/ally to replace the nylon bush.

Should be simple enough fix that'll see me in good shape to get to the 8 Balls rallye.

[Warkton Tornado No.1]

As the bracket appears to be spaced away from the case cover by tubular spacers, I would suggest that long term the set-up be re-engineered with the bolts & spacers being replaced with longer M6 engineering studs into the case & M6 pillars to replace the spacers. Such a modification will give the case threads an easier life. M6 hexagonal pillars in steel or stainless are obtainable from the likes of Toolstation etc.

Just for information, IMO aftermarket manufacturers of Lambretta exhausts seem to have a pre-occupation with utilising solid spacers when manufacturing the mounts for their exhausts. Two stroke exhausts like to vibrate to enable them to work more efficiently & last. That’s why spring mounts are used in the barrel area or as close as is practicable. An exhaust mounting can usually be improved by substituting proper anti-vibration mounts in place of the solid mounts.

To my eyes, the rear brake lever appears to be not located in the best position. If we call the current position twelve O’clock, it would be better re-positioned toward half past ten

[LambrettaMarky]

As the bracket appears to be spaced away from the case cover by tubular spacers, I would suggest that long term the set-up be re-engineered with the bolts & spacers being replaced with longer M6 engineering studs into the case & M6 pillars to replace the spacers. Such a modification will give the case threads an easier life. M6 hexagonal pillars in steel or stainless are obtainable from the likes of Toolstation etc.

Just for information, IMO aftermarket manufacturers of Lambretta exhausts seem to have a pre-occupation with utilising solid spacers when manufacturing the mounts for their exhausts. Two stroke exhausts like to vibrate to enable them to work more efficiently & last. That’s why spring mounts are used in the barrel area or as close as is practicable. An exhaust mounting can usually be improved by substituting proper anti-vibration mounts in place of the solid mounts.

To my eyes, the rear brake lever appears to be not located in the best position. If we call the current position twelve O’clock, it would be better re-positioned toward half past ten

Thank you for the observations & comments.

Brake lever has very little throw on it, so is effective pretty much straight away in a near vertical position that offers a perpendicular (almost) cable pull. I will double check though.

DO you mean a male thread into the case from a pillar that has a female thread to then accept the mount bolt? Correct that a anti-vibration mount would be a good idea too.

I'm off to have a look - Cheers...

[Warkton Tornado No.1]

DO you mean a male thread into the case from a pillar that has a female thread to then accept the mount bolt? Correct that a anti-vibration mount would be a good idea too.

I'm off to have a look - Cheers...

I was referring to the rear - white - mount that could be replaced by an anti-vibration mount. They are often called bobbins & were used extensively by the racing fraternity. However, my belief is that the whole of an exhaust is best mounted via A-V mounts rather than having any part of it constrained by solid mounts.

RS Components used to have a range of A-V mounts with various thread sizes male &/or female & their on-line catalogue is an excellent means of research for such items.

[LambrettaMarky]

DO you mean a male thread into the case from a pillar that has a female thread to then accept the mount bolt? Correct that a anti-vibration mount would be a good idea too.

I'm off to have a look - Cheers...

I was referring to the rear - white - mount that could be replaced by an anti-vibration mount. They are often called bobbins & were used extensively by the racing fraternity. However, my belief is that the whole of an exhaust is best mounted via A-V mounts rather than having any part of it constrained by solid mounts.

RS Components used to have a range of A-V mounts with various thread sizes male &/or female & their on-line catalogue is an excellent means of research for such items.

Got it - Thx. I have 'for now' machined a flat on the nylon spacer to clear the panel. It may well be enough as I'm no high mileage junkie on the GP... Found I had lost a case retaining nut so sorted that and am now changing the oil while I'm at it!

[LambrettaMarky]

Exhaust Mount Mod by KTM Marky, on Flickr

Rather untechnical, but should work and sorted the missing case nut, changed the oil so good to go for a scoot now..

[Warkton Tornado No.1]

Rather untechnical, but should work and sorted the missing case nut, changed the oil so good to go for a scoot now..

As you mention oil & you being a biker as well, you’re probably more aware than many that ATF is often substituted for wet clutch gearboxes. I’ve been using it for years in 25+ BHP engines with six plate minimum clutches & it works extremely well. If anything, it’s an improvement as it actually cured one engine clutches tendency to slip. I have found that it stays cleaner going by the discolouration by comparison with ST90. Cheap as chips too

[LambrettaMarky]

Rather untechnical, but should work and sorted the missing case nut, changed the oil so good to go for a scoot now..

As you mention oil & you being a biker as well, you’re probably more aware than many that ATF is often substituted for wet clutch gearboxes. I’ve been using it for years in 25+ BHP engines with six plate minimum clutches & it works extremely well. If anything, it’s an improvement as it actually cured one engine clutches tendency to slip. I have found that it stays cleaner going by the discolouration by comparison with ST90. Cheap as chips too

I use Putoline ATF in my BSA B40 trials bike gearbox. I did have some non EP 90 also Putoline that was in the GP from Cam Lam, but I didn't have enough so mixed it with some EP90 I had on the shelf from my old TR4 days.. let's see..

[Warkton Tornado No.1]

I use Putoline ATF in my BSA B40 trials bike gearbox. I did have some non EP 90 also Putoline that was in the GP from Cam Lam, but I didn't have enough so mixed it with some EP90 I had on the shelf from my old TR4 days.. let's see..

If ‘EP’ means Extreme Pressure then it is likely to be unsuitable as the additives contained will prevent the contact required between friction & the non-friction plates.

[LambrettaMarky]

I use Putoline ATF in my BSA B40 trials bike gearbox. I did have some non EP 90 also Putoline that was in the GP from Cam Lam, but I didn't have enough so mixed it with some EP90 I had on the shelf from my old TR4 days.. let's see..

If ‘EP’ means Extreme Pressure then it is likely to be unsuitable as the additives contained will prevent the contact required between friction & the non-friction plates.

It does and I thought it worth a punt seeing as it's there.. It could slip - let's see.